Tuberculosis (TB) is a serious infection that can affect the lungs and other parts of the body. The usual way to treat TB is to take 4 medicines by mouth every day for 2 months, then take 2 of the same medicines for 4 more months, for a total of 6 months. The purpose of this study is to see if taking 4 months of TB medicines is as effective in curing some TB patients as taking 6 months of TB medicines. Study participants will include 758 human immunodeficiency virus (HIV)-non-infected individuals, ages 18-60. Participants will be treated with 4 standard drugs called isoniazid, rifampicin, pyrazinamide and ethambutol. All individuals will take TB medicines for at least 4 months. After 4 months of treatment, if no TB germs are growing in sputum samples, participants will be assigned to either stop taking TB medicine (4 months of treatment) or to continue taking TB drugs for 2 more months (6 months of treatment). Participants will be involved in study procedures for up to 30 months.

A Prospective Study of Shortening the Duration of Standard Short Course Chemotherapy From 6 Months to 4 Months in HIV-non-infected Patients With Fully Drug-Susceptible, Non-cavitary Pulmonary Tuberculosis With Negative Sputum Cultures After 2 Months of Anti-TB Treatment

Patients who presented with TB after completion of study phase treatment but before the end of follow-up were classified as relapses. A bacteriologic relapse was defined as a patient who became consistently culture-positive [defined as at least 1 of the following]: (a) at least 1 sputum mycobacterial culture growing at least 10 colonies of MTB on solid medium; (b) 2 or more respiratory secretion cultures that are positive for MTB in liquid media; or (c) any culture from an extrapulmonary site that is positive for MTB during follow-up after successful completion of initial anti-TB treatment.

Patients who presented with TB after completion of study phase treatment but before the end of follow-up were classified as relapses. A bacteriologic relapse was defined as a patient who became consistently culture-positive [defined as at least 1 of the following]: (a) at least 1 sputum mycobacterial culture growing at least 10 colonies of MTB on solid medium; (b) 2 or more respiratory secretion cultures that are positive for MTB in liquid media; or (c) any culture from an extrapulmonary site that is positive for MTB during follow-up after successful completion of initial anti-TB treatment.

Secondary Outcome Measures:

Treatment Failures or Relapses at 2 Years After Completion of TB Treatment: Intention to Treat [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]

A culture-positive treatment failure was defined as initial culture conversion but subsequent reversion to culture positivity. A clinical treatment failure was defined as a patient with clinical and/or radiographic evidence of progressive tuberculosis not confirmed by a positive culture after 4 or more months of anti-TB treatment while still receiving treatment. Patients who defaulted before completing study treatment and returned later with culture-positive tuberculosis were termed failures after non-adherence.

Treatment Failures or Relapses at 2 Years After Completion of TB Treatment: Per Protocol [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]

A culture-positive treatment failure was defined as initial culture conversion but subsequent reversion to culture positivity. A clinical treatment failure was defined as a patient with clinical and/or radiographic evidence of progressive tuberculosis not confirmed by a positive culture after 4 or more months of anti-TB treatment while still receiving treatment. Patients who defaulted before completing study treatment and returned later with culture-positive tuberculosis were termed failures after non-adherence.

Relapses at 1 and 2 Years [ Time Frame: 1 and 2 years after successful completion of initial anti-TB treatment ] [ Designated as safety issue: Yes ]

Acquired Drug Resistance in Patients Who Relapsed [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Hydrazide of isonicotininc acid; antimicrobial activity is limited to mycobacteria where it inhibits the synthesis of mycolic acids.

Drug: Ethambutol

Mycobacteriostatic agent given to prevent emergence of drug resistance to other 1st line drugs; dosages are 15-25 milligram (mg)/ kilogram (kg)/day (d).

Detailed Description:

Tuberculosis (TB) is a major global health problem. TB is the current leading cause of death due to an identifiable infectious agent worldwide. One of the highest priorities for tuberculosis control programs is to shorten anti-TB treatment while maintaining its effectiveness. Current 6-month short course chemotherapy regimens are over 95% effective for the treatment of tuberculosis when fully administered. Six months is a long time, however, and patients frequently discontinue anti-TB treatment once their symptoms have improved. The duration of standard short course chemotherapy is one of the major obstacles to its successful application and poses substantial challenges to programs with respect to patient adherence, program resource needs, and logistical requirements for directly observed therapy. The primary objective of this study is to assess the efficacy of shortening anti-TB treatment to 4 months in human immunodeficiency virus (HIV)-non-infected adults with drug-susceptible, non-cavitary pulmonary tuberculosis who convert their sputum culture to negative after 2 months of treatment. Secondary objectives of this study include: comparing pre-treatment sputum bacillary load in patients with and without cavitary disease; compare time after inoculation of BACTEC or Mycobacteria growth indicator tube (MGIT) liquid culture media until positive with semi-quantitative sputum acid fast bacteria (AFB) smear and culture on solid media as measures of pre-treatment sputum bacillary load; and determining the influence of immunologic characteristics of subjects pre-treatment, during treatment and at the end of therapy on rate of bacillary clearance and risk for relapse. A total of 758 HIV-non-infected adults, male or female, 18-60 years of age, with newly diagnosed initial episodes of sputum AFB smear-positive or -negative, culture-positive, non-cavitary, drug-susceptible pulmonary TB who are sputum culture negative after 2 months of anti-TB treatment will be randomly assigned to complete a total of 4 or 6 months of anti-TB therapy. The experimental regimen will include a total of 4 months of anti-TB treatment [2 months of daily isoniazid (INH), rifampicin, pyrazinamide and ethambutol followed by 2 months of daily INH and rifampicin]. The comparative regimen will include a total of 6 months standard short course anti-TB chemotherapy (2 months of daily INH, rifampicin, pyrazinamide and ethambutol followed by 4 months of daily INH and rifampicin). Subjects will be involved in study related procedures for approximately 30 months after beginning the initial anti-TB treatment.

Eligibility

Ages Eligible for Study:

18 Years to 60 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Adults, male or female, aged 18-60.

Newly diagnosed initial episodes of pulmonary tuberculosis. Sputum smear-positive and -negative patients are eligible for enrollment. The diagnosis of tuberculosis must be confirmed by culture. Acid fast bacteria (AFB) smear positive patients found later not to have tuberculosis (TB) (i.e. those with non-tuberculous mycobacterial disease) and those without culture confirmation [at least one culture on solid media growing > 10 colonies of Mycobacterium tuberculosis (MTB) or a positive BACTEC or Mycobacteria growth indicator tube (MGIT) enriched liquid culture growing MTB] will be removed from the study.

Chest X-ray and clinical findings consistent with tuberculosis.

Hemoglobin greater than or equal to 8 gm/dL (greater than or equal to 5.0 mmol/L).

Final determination of eligibility will be made after review of drug susceptibility testing results on an initial sputum isolate and results of all sputum cultures.

Pregnant patients may not be enrolled in the study. Patients in the 4 month arm who become pregnant during months 5 and 6 of study participation will be dropped from the study and receive an additional 2 months of treatment with INH and rifampicin.

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00130247